Controls on Eurasian coastal sea ice formation, melt onset and decay from ERS scatterometry: Regional contrasts and effects of river influx

Regional and local patterns in the formation, melt onset and disappearance of coastal first-year sea ice (FYI) are observed in the Eurasian Arctic using the C-band (5.3 GHz) European Remote Sensing Satellite (ERS) radar scatterometers. Near-daily time-series (1991-1999) of the radar backscatter coef...

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Published in:International Journal of Remote Sensing
Main Authors: Frey, K. E., Smith, L. C., Alsdorf, D. E.
Format: Text
Language:unknown
Published: Clark Digital Commons 2003
Subjects:
ice
Online Access:https://commons.clarku.edu/faculty_geography/252
https://doi.org/10.1080/0143116031000101684
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spelling ftclarkuniv:oai:commons.clarku.edu:faculty_geography-1251 2023-09-05T13:17:46+02:00 Controls on Eurasian coastal sea ice formation, melt onset and decay from ERS scatterometry: Regional contrasts and effects of river influx Frey, K. E. Smith, L. C. Alsdorf, D. E. 2003-12-20T08:00:00Z https://commons.clarku.edu/faculty_geography/252 https://doi.org/10.1080/0143116031000101684 unknown Clark Digital Commons https://commons.clarku.edu/faculty_geography/252 doi:10.1080/0143116031000101684 https://doi.org/10.1080/0143116031000101684 Geography sea ice artificial satellites ice oceanography Eurasia Geography Social and Behavioral Sciences text 2003 ftclarkuniv https://doi.org/10.1080/0143116031000101684 2023-08-14T06:15:24Z Regional and local patterns in the formation, melt onset and disappearance of coastal first-year sea ice (FYI) are observed in the Eurasian Arctic using the C-band (5.3 GHz) European Remote Sensing Satellite (ERS) radar scatterometers. Near-daily time-series (1991-1999) of the radar backscatter coefficient normalized to an incident angle of 40° (σ040) and the backscatter-incident angle relationship (B) are examined for test sites near the Severnaya Dvina, Mezen, Pechora, Ob', Yenisci, Khatanga, Lena, Indigirka and Kolyma rivers. Melt onset of the sea ice surface is associated with abrupt changes in σ040, with values converging towards ∼ -17 dB. As such, whether backscatter increases or decreases at melt onset is largely determined by contrast with pre-melt backscatter levels. The presence or absence of FYI is designated from low or high values of B, respectively, whereas the addition of an anisotropy criterion further improves discrimination of FYI from open water. A strong regional pattern is seen in the daily temporal variability of both melt onset and ice cover, with maximum variability in the Barents and Kara seas and decreasing variability eastward. Similarly, significant contrasts in the seasonal duration of ice cover are found between western and eastern sites. Seasonal ice cover persists ∼ 144 days for sites in the Barents Sea, but ∼ 293 days for sites farther east in the East Siberian Sea. We speculate that our observed west-east contrasts are due to North Atlantic modulation of salinity, air temperature and cyclone density. Rivers also exert a local effect on ice cover, causing earlier formation (∼ 4 days) and earlier disappearance (∼ 17 days) near river mouths. The hydrological influence of rivers is potentially strong in the Kara, Laptev and East Siberian seas, but weak or absent in the Barents Sea. Text Arctic Barents Sea dvina East Siberian Sea Kara-Laptev khatanga laptev North Atlantic Pechora Sea ice Clark University: Clark Digital Commons Arctic Barents Sea East Siberian Sea ENVELOPE(166.000,166.000,74.000,74.000) Indigirka ENVELOPE(149.609,149.609,70.929,70.929) Kolyma ENVELOPE(161.000,161.000,69.500,69.500) Severnaya Dvina ENVELOPE(40.494,40.494,64.532,64.532) International Journal of Remote Sensing 24 24 5283 5315
institution Open Polar
collection Clark University: Clark Digital Commons
op_collection_id ftclarkuniv
language unknown
topic sea ice
artificial satellites
ice
oceanography
Eurasia
Geography
Social and Behavioral Sciences
spellingShingle sea ice
artificial satellites
ice
oceanography
Eurasia
Geography
Social and Behavioral Sciences
Frey, K. E.
Smith, L. C.
Alsdorf, D. E.
Controls on Eurasian coastal sea ice formation, melt onset and decay from ERS scatterometry: Regional contrasts and effects of river influx
topic_facet sea ice
artificial satellites
ice
oceanography
Eurasia
Geography
Social and Behavioral Sciences
description Regional and local patterns in the formation, melt onset and disappearance of coastal first-year sea ice (FYI) are observed in the Eurasian Arctic using the C-band (5.3 GHz) European Remote Sensing Satellite (ERS) radar scatterometers. Near-daily time-series (1991-1999) of the radar backscatter coefficient normalized to an incident angle of 40° (σ040) and the backscatter-incident angle relationship (B) are examined for test sites near the Severnaya Dvina, Mezen, Pechora, Ob', Yenisci, Khatanga, Lena, Indigirka and Kolyma rivers. Melt onset of the sea ice surface is associated with abrupt changes in σ040, with values converging towards ∼ -17 dB. As such, whether backscatter increases or decreases at melt onset is largely determined by contrast with pre-melt backscatter levels. The presence or absence of FYI is designated from low or high values of B, respectively, whereas the addition of an anisotropy criterion further improves discrimination of FYI from open water. A strong regional pattern is seen in the daily temporal variability of both melt onset and ice cover, with maximum variability in the Barents and Kara seas and decreasing variability eastward. Similarly, significant contrasts in the seasonal duration of ice cover are found between western and eastern sites. Seasonal ice cover persists ∼ 144 days for sites in the Barents Sea, but ∼ 293 days for sites farther east in the East Siberian Sea. We speculate that our observed west-east contrasts are due to North Atlantic modulation of salinity, air temperature and cyclone density. Rivers also exert a local effect on ice cover, causing earlier formation (∼ 4 days) and earlier disappearance (∼ 17 days) near river mouths. The hydrological influence of rivers is potentially strong in the Kara, Laptev and East Siberian seas, but weak or absent in the Barents Sea.
format Text
author Frey, K. E.
Smith, L. C.
Alsdorf, D. E.
author_facet Frey, K. E.
Smith, L. C.
Alsdorf, D. E.
author_sort Frey, K. E.
title Controls on Eurasian coastal sea ice formation, melt onset and decay from ERS scatterometry: Regional contrasts and effects of river influx
title_short Controls on Eurasian coastal sea ice formation, melt onset and decay from ERS scatterometry: Regional contrasts and effects of river influx
title_full Controls on Eurasian coastal sea ice formation, melt onset and decay from ERS scatterometry: Regional contrasts and effects of river influx
title_fullStr Controls on Eurasian coastal sea ice formation, melt onset and decay from ERS scatterometry: Regional contrasts and effects of river influx
title_full_unstemmed Controls on Eurasian coastal sea ice formation, melt onset and decay from ERS scatterometry: Regional contrasts and effects of river influx
title_sort controls on eurasian coastal sea ice formation, melt onset and decay from ers scatterometry: regional contrasts and effects of river influx
publisher Clark Digital Commons
publishDate 2003
url https://commons.clarku.edu/faculty_geography/252
https://doi.org/10.1080/0143116031000101684
long_lat ENVELOPE(166.000,166.000,74.000,74.000)
ENVELOPE(149.609,149.609,70.929,70.929)
ENVELOPE(161.000,161.000,69.500,69.500)
ENVELOPE(40.494,40.494,64.532,64.532)
geographic Arctic
Barents Sea
East Siberian Sea
Indigirka
Kolyma
Severnaya Dvina
geographic_facet Arctic
Barents Sea
East Siberian Sea
Indigirka
Kolyma
Severnaya Dvina
genre Arctic
Barents Sea
dvina
East Siberian Sea
Kara-Laptev
khatanga
laptev
North Atlantic
Pechora
Sea ice
genre_facet Arctic
Barents Sea
dvina
East Siberian Sea
Kara-Laptev
khatanga
laptev
North Atlantic
Pechora
Sea ice
op_source Geography
op_relation https://commons.clarku.edu/faculty_geography/252
doi:10.1080/0143116031000101684
https://doi.org/10.1080/0143116031000101684
op_doi https://doi.org/10.1080/0143116031000101684
container_title International Journal of Remote Sensing
container_volume 24
container_issue 24
container_start_page 5283
op_container_end_page 5315
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